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the HIV-1-specific T-cell responses. CD100 was demonstrated to play a relevant role in immune responses in various pathological processes and may be responsible for immune dysregulation during HIV-1 infection. We investigated the function of CD72/CD100, and PD-1/PDL-1 axes on T and B cells in HIV-infected individuals and in healthy individuals. We analyzed the frequencies and fluorescence intensities of these four markers on CD4+, CD8+ T and B cells. Marker expressions were increased during active HIV-1 infection. CD100 frequency on T cells was positively associated with the expression of PD-1 and PD-L1 on T cells from HIV-infected treatment-naïve individuals. In addition, the frequency of CD72-expressing T cells was associated with interferon gamma (IFN-γ) production in HIV-infected treatment-naïve individuals. Our data suggest that the CD72/CD100 and PD-1/PD-L1 axes may jointly participate in dysregulation of immunity during HIV-1 infection and could partially explain the immune systems' hyper-activation and exhaustion.

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been described. Moreover, CD70 is implicated in tumor cell and regulatory T cell survival through interaction with its ligand, CD27. In this review, we summarize the targetable expression patterns of CD70 in a wide range of malignancies and the promising mechanism of anti-CD70 therapy in stimulating the anti-tumor immune response. In addition, we will discuss clinical data and future combination strategies.

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otein kinase phosphorylation. METHODS: We evaluated the expression of CD70 in biopsies and melanoma cell lines. Using melanoma cell lines positive or not for CD70, we analysed CD70 function on melanoma progression. RESULTS: We report CD70 expression in human melanoma cell lines and tumour cells from melanoma biopsies. This expression was observed in 95% of primary melanomas but only 37% of metastases. Both monomeric and trimeric forms of CD70 were detected in tumour cell membrane fractions, whereas cytoplasmic fractions contained almost exclusively monomeric CD70. In vitro and in vivo experiments demonstrated that CD70 expression inhibited melanoma cell migration, invasion and pulmonary metastasis implantation independently of the tumour immune microenvironment. Increasing the levels of the trimeric form of CD70 through monoclonal antibody binding led to an increase in CD70+ melanoma cell invasiveness through MAPK pathway activation, RhoE overexpression, ROCK1 and MYPT1 phosphorylation decrease, and stress fibres and focal adhesions disappearance. CONCLUSIONS: Our results describe a new non-immunological function of melanoma-expressed CD70, which involves melanoma invasiveness through MAPK pathway, RhoE and cytoskeletal modulation.

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yle='font-weight:700;'>CD73-generated adenosine exerts anti-inflammatory effects. However, the expression and function of CD73 in pro-inflammatory M1 and in immunosuppressive M2 macrophages is largely unknown. Here we show that CD73 expression and enzyme activity were induced in in vitro polarized pro-inflammatory human M(LPS+TNF) monocytes/macrophages, while CD73 was absent from immunosuppressive M(IL-4+M-CSF)-polarized macrophages. Inhibition of CD73 activity with the inhibitor AMPCP did not affect the polarization of human monocytes. In mice, CD73 was present on resident peritoneal macrophages. In striking contrast, elicited peritoneal macrophages remained CD73 negative regardless of their polarization towards either a pro-inflammatory M(LPS) or anti-inflammatory M(IL-4c) direction. Finally, the ability of peritoneal macrophages to polarize to pro- and anti-inflammatory cells was perfectly normal in CD73-deficient mice in vivo. These data indicate that, in contrast to other major leukocyte subpopulations, CD73 activity on macrophages does not play a major role in their polarization and that in mice host CD73 on any cell type is not required in vivo for peritoneal macrophage polarization towards either a pro- or an anti-inflammatory direction.

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otidase) is important for the conversion of 5'-AMP to adenosine, we investigated whether CD73 is necessary for normal renal sympathetic neurotransmission. In isolated kidneys from CD73 wild-type mice (CD73 +/+; n=17) perfused at a constant rate with Tyrode's solution, RSNS increased perfusion pressure by 17+/-4, 36+/-8 and 44+/-10 mm Hg at 3, 5 and 7 Hz, respectively. Similar responses were elicited from kidneys isolated from CD73 knockout mice (CD73 -/-; n=13; 28+/-11, 43+/-10 and 44+/-10 mm Hg at 3, 5 and 7 Hz, respectively); and a high concentration (100 mumol/L) of alpha,beta-methyleneadenosine 5'-diphosphate (CD73 inhibitor) did not alter responses to RSNS in C57BL/6 mouse kidneys (n=5; 21+/-5, 36+/-8 and 43+/-9 at 3, 5 and 7 Hz, respectively). Measurements of renal venous adenosine and inosine (adenosine metabolite) by liquid chromatography-tandem mass spectrometry demonstrated that the metabolism of exogenous 5'-AMP to adenosine and inosine was similar in CD73 -/- versus CD73 +/+ kidneys. A1 receptor mRNA expression was increased in CD73 -/- kidneys, and 2-chloro-N6-cyclopentyladenosine (0.1 mumol/L; A1 receptor agonist) enhanced renovascular responses to norepinephrine more in CD73 -/- versus CD73 +/+ kidneys. We conclude that CD73 is not essential for renal sympathetic neurotransmission because in the absence of renal CD73 other enzymes metabolize 5'-AMP to adenosine and because of compensatory upregulation of postjunctional coincident signaling between norepinephrine and adenosine.

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h at the mRNA and protein levels. Secondly, recombinant CD73 interference and overexpression lentiviruses were used, respectively. Colony formation assay, CCK-8 assay and flow cytometry were used to investigate the impact of CD73 on colorectal cancer cell proliferation and cell cycle distribution. Then, adenosine and CD73 enzyme activity inhibitor (APCP) were used to study the effect of CD73 on Epidermal growth factor receptor (EGFR) and beta-catenin/cyclin D1 signaling pathways. Finally, a human colorectal cancer transplantation nude mouse model was used to observe the effect of CD73 on tumor growth in vivo. As the results showed, CD73 was highly expressed in the colorectal cancer cell lines. CD73 promoted colorectal cancer cell proliferation both in vivo and in vitro. CD73 activated EGFR and the beta-catenin/cyclin D1 signaling pathways through its enzyme and non-enzyme activities. All of the results confirmed that CD73 promotes the growth of human colorectal cancer cells through EGFR and the beta-catenin/cyclin D1 signaling pathway. CD73 may be used as a valuable biomarker of colorectal cancer.

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-cell receptor (pre-BCR) complex. A 2-year-old girl was found to have a homozygous splice defect in Igalpha, a transmembrane protein that forms part of the Igalpha/Igbeta signal-transduction module of the pre-BCR. Studies in mice suggest that the Igbeta component of the pre-BCR influences V-DJ rearrangement before cell-surface expression of mu heavy chain. To determine whether Igalpha plays a similar role, we compared B-cell development in an Igalpha-deficient patient with that seen in a mu heavy chain-deficient patient. By immunofluorescence, both patients had a complete block in B-cell development at the pro-B to pre-B transition; both patients also had an equivalent number and diversity of rearranged V-DJ sequences. These results indicate that mutations in Igalpha can be a cause of agammaglobulinemia. Furthermore, they suggest that Igalpha does not play a critical role in B-cell development until it is expressed, along with mu heavy chain, as part of the pre-BCR.

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to other cancers, CD73 is markedly downregulated in poorly differentiated and advanced-stage endometrial carcinoma compared with levels in normal endometrium and low-grade tumors. In murine models, CD73 deficiency led to a loss of endometrial epithelial barrier function, and pharmacological CD73 inhibition increased in vitro migration and invasion of endometrial carcinoma cells. Given that CD73-generated adenosine is central to regulating tissue protection and physiology in normal tissues, we hypothesized that CD73-generated adenosine in endometrial carcinoma induces an innate reflex to protect epithelial integrity. CD73 associated with cell-cell contacts, filopodia, and membrane zippers, indicative of involvement in cell-cell adhesion and actin polymerization-dependent processes. We determined that CD73-generated adenosine induces cortical actin polymerization via adenosine A1 receptor (A1R) induction of a Rho GTPase CDC42-dependent conformational change of the actin-related proteins 2 and 3 (ARP2/3) actin polymerization complex member N-WASP. Cortical F-actin elevation increased membrane E-cadherin, beta-catenin, and Na(+)K(+) ATPase. Together, these findings reveal that CD73-generated adenosine promotes epithelial integrity and suggest why loss of CD73 in endometrial cancer allows for tumor progression. Moreover, our data indicate that the role of CD73 in cancer is more complex than previously described.

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, limiting potential targets to surface antigens that are trafficked to lysosomes. CD79a and CD79b comprise the hetrodimeric signaling component of the B-cell receptor, and are attractive targets for the use of ADCs because they are B-cell-specific, expressed in non-Hodgkin lymphomas (NHL), and are trafficked to a lysosomal-like compartment as part of antigen presentation. We show here that the stable-linker ADCs anti-CD79b-MCC-DM1 and anti-CD79b-MC-MMAF are capable of target-dependent killing of nonHodgkin lymphoma cell lines in vitro. Further, these 2 ADCs are equally effective as low doses in xenograft models of follicular, mantle cell, and Burkitt lymphomas, even though several of these cell lines express relatively low levels of CD79b in vivo. In addition, we demonstrate that anti-CD79b ADCs were more effective than anti-CD79a ADCs and that, as hypothesized, anti-CD79b antibodies downregulated surface B-cell receptor and were trafficked to the lysosomal-like major histocompatibility complex class II-positive compartment MIIC. These results suggest that anti-CD79b-MCC-DM1 and anti-CD79b-MC-MMAF are promising therapeutics for the treatment of NHL.

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A2A adenosine receptor (A2AR) that mediates adenosine signaling in leuokocytes, by using compound gene-targeted mice or therapeutics that target these molecules, limits tumor initiation, growth, and metastasis. This tumor control requires effector lymphocytes and interferon-gamma, while antibodies targeting CD73 promote an optimal therapeutic response in vivo when engaging activating Fc receptors. In a two-way mixed leukocyte reaction using a fully human anti-CD73, we demonstrated that Fc receptor binding augmented the production of proinflammatory cytokines.

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quired for surface expression of mIg and BCR signaling. B cells from chronic lymphocytic leukemia (B-CLL) frequently express low to undetectable surface Ig, as well as CD79b protein. Recent work described genetic aberrations affecting B29 expression and/or function in B-CLL. Because the prevalence of CLL is increased among first degree relatives, we analyzed the B29 gene in 10 families including 2 affected members each. A few silent or replacement mutations were observed at the genomic level, which never lead to truncated CD79b protein. Both members of the same family did not harbor the same mutations. However, a single silent base change in the B29 extracellular domain, corresponding to a polymorphism, was detected on 1 allele of most patients. These results indicate that the few mutations observed in the B29 gene in these patients do not induce structural abnormalities of the CD79b protein and thus do not account for its low surface expression in B-CLL. Furthermore, genetic factors were not implicated, because identical mutations were not observed among 2 members of the same family.

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enhances the expression of CD74, which interacts with its ligand, macrophage migration inhibitory factor (MIF), and thereby activates the PI3K/AKT pathway in melanoma, promoting tumor survival. IFN-gamma increased phosphorylation of AKT Ser473 and upregulated total cell surface expression of CD74 in human melanoma cell lines tested. CD74 was highly expressed in melanoma tissues. Moreover, the expression of CD74 on tumor cells correlated with plasma IFN-gamma levels in melanoma patient samples. In our analysis of melanoma cell lines, all produced MIF constitutively. Blockade of CD74-MIF interaction reduced AKT phosphorylation and expression of pro-tumorigenic molecules, including IL-6, IL-8, and BCL-2. Inhibition of CD74-MIF interaction significantly suppressed tumor growth in the presence of IFN-gamma in our xenograft mouse model. Thus, we conclude that IFN-gamma promotes melanoma cell survival by regulating CD74-MIF signaling, suggesting that targeting the CD74-MIF interaction under IFN-gamma-stimulatory conditions would be an effective therapeutic approach for melanoma.

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tyrosine kinase (BTK) gene is mostly identified. Recent studies have shown that mutations in the gene for mu heavy chain (IGHM) and for other components of the pre-B cell receptor complex, including lambda5/14.1 (IGLL1) or Igalpha (CD79a), can cause a disorder that is clinically similar to XLA. In a genetic survey of XLA in Turkey, we examined possible mutations in the IGHM, IGLL1, and Igalpha genes in some male patients with presumed XLA who did not have identifiable BTK mutations. We found an eight-year-old boy with a novel homozygous mutation in the Igalpha gene (IVS2+1G>A) causing B cell defect. This is the second case of agammaglobulinemia due to an Igalpha (CD79a) deficiency in the world.

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e='font-weight:700;'>CD79b). Because the expression of the extracellular Ig-like domain of CD79b has been reported to be absent in the cells of most CLL cases, we have investigated the molecular mechanisms that may account for this defect. Peripheral blood lymphocytes (PBL) from 50 patients and two cell lines (MEC1, MEC2) obtained from the PBL of one of them were studied. MEC1, MEC2, and 75% of CLL cases did not express detectable levels of the extracellular Ig-like domain of CD79b, which was nevertheless present in greater than 80% CD19(+) cells from normal donors. In healthy subjects the expression of CD79b was equally distributed in CD5(+) and CD5(-) B-cell subsets. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of CD79b RNA from all patients and from MEC1 and MEC2 cell lines consistently yielded two fragments of different size (709 bp and 397 bp). The 709-bp band corresponds to CD79b entire transcript; the 397-bp band corresponds to an alternatively spliced form lacking exon 3 that encodes the extracellular Ig-like domain. Both fragments were also visible in normal PBL. The expression of the 397-bp fragment was increased in normal activated B cells, while no difference was seen between CD5(+) and CD5(-) B cells. To obtain a more accurate estimate of the relative proportions of the two spliced forms, a radioactive PCR was performed in 13 normal and 22 B-CLL samples and the results analyzed using a digital imager. The mean value of the CD79b to the CD79b internally deleted ratio was 0.64 +/- 0.20 SD in normal donors and 0.44 +/- 0.27 SD in B-CLL (P =.01). Direct sequencing of 397-bp RT-PCR products and of genomic DNA corresponding to exon 3 from MEC1, MEC2, their parental cells, and five fresh B-CLL samples did not show any causal mutation. Single-strand conformation polymorphism analysis of exon 3 performed in 18 additional B-CLL cases showed a single abnormal shift corresponding to a TGT --> TGC polymorphic change at amino acid 122. We propose a role for the alternative splicing of CD79b gene in causing the reduced expression of BCR on the surface of B-CLL cells. As normal B cells also present this variant, the mechanism of CD79b posttranscriptional regulation might reflect the activation stage of the normal B cell from which B-CLL derives.

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of tumours and serum revealed genetic ablation of CatS leads to the depletion of several pro-inflammatory chemokines, most notably, CCL2. This observation was validated in vitro, where shRNA depletion of CatS resulted in reduced CCL2 expression. This regulation is transcriptionally mediated, as evident from RT-PCR analysis and CCL2 promoter studies. We revealed that CatS regulation of CCL2 is modulated through CD74 (also known as the invariant chain), a known substrate of CatS and a mediator of NFkB activity. Furthermore, CatS and CCL2 show a strong clinical correlation in brain, breast and colon tumours. In summary, these results highlight a novel mechanism by which CatS controls CCL2, which may present a useful pharmacodynamic marker for CatS inhibition.

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adaptive immunity. OBJECTIVE: To test the hypothesis that CD70 and immunologic memory contribute to the blood pressure elevation and renal dysfunction mediated by repeated hypertensive challenges. METHODS AND RESULTS: We imposed repeated hypertensive challenges using either N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME)/high salt or repeated angiotensin II stimulation in mice. During these challenges effector memory T cells (T(EM)) accumulated in the kidney and bone marrow. In the L-NAME/high-salt model, memory T cells of the kidney were predominant sources of interferon-gamma and interleukin-17A, known to contribute to hypertension. L-NAME/high salt increased macrophage and dendritic cell surface expression of CD70 by 3- to 5-fold. Mice lacking CD70 did not accumulate T(EM) cells and did not develop hypertension to either high salt or the second angiotensin II challenge and were protected against renal damage. Bone marrow-residing T(EM) cells proliferated and redistributed to the kidney in response to repeated salt feeding. Adoptively transferred T(EM) cells from hypertensive mice homed to the bone marrow and spleen and expanded on salt feeding of the recipient mice. CONCLUSIONS: Our findings illustrate a previously undefined role of CD70 and long-lived T(EM) cells in the development of blood pressure elevation and end-organ damage that occur on delayed exposure to mild hypertensive stimuli. Interventions to prevent repeated hypertensive surges could attenuate formation of hypertension-specific T(EM) cells.

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d its role in the regulatory function of gammadelta T cells in experimental autoimmune uveitis (EAU). We found that gammadelta T cells expressed different amounts of CD73 during the different stages of EAU and that low CD73 expression on gammadelta T cells correlated with enhanced Th17 response-promoting activity. Functional comparison of CD73-deficient and wild-type B6 (CD73+/+) mice showed that failure to express CD73 decreased both the enhancing and suppressive effects of gammadelta T cells on EAU. We also demonstrated that gammadelta T cells expressed different amounts of CD73 when activated by different pathways, which enabled them to either enhance or inhibit an adaptive immune response. Our results demonstrate that targeting CD73 expression on gammadelta T cells may allow us to manipulate their pro- or anti-inflammatory effect on Th17 responses.

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evelopment or function is unknown. Here, we demonstrate that CD73 is progressively upregulated on germinal center (GC) B cells following immunization, is expressed at even higher levels among T follicular helper cells, but is absent among plasma cells (PC) and plasmablasts (PB). We analyzed the T-dependent B cell response in CD73 knockout mice (CD73KO). During the early response, CD73KO and wild type (WT) mice formed GCs, MBCs and splenic PBs and PCs similarly, and MBCs functioned similarly in the early secondary response. Late in the primary response, however, bone marrow (BM) PCs were markedly decreased in CD73KO animals. Tracking this phenotype, we found that CD73 expression was required on BM-derived cells for optimal BM PC responses. However, deletion of CD73 from either B or T lymphocytes alone did not recapitulate the phenotype. This suggests that CD73 expression is sufficient on either cell type, consistent with its function as an ectoenzyme. Together, these findings suggest that CD73-dependent adenosine signaling is prominent in the mature GC and required for establishment of the long-lived PC compartment, thus identifying a novel role for CD73 in humoral immunity.

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the role of the CD73/adenosine pathway in immune modulation by MSCs using a mouse model of experimental autoimmune uveitis (EAU). Moreover, we examined the in vitro modulatory effect of MSCs mediated through the CD73/adenosine pathway in human and mouse T cells. We found that the severity of EAU was significantly attenuated by MSCs; however, most therapeutic effects of MSCs were lost by pretreatment with a CD73 inhibitor. The inhibitory mechanism of MSCs might be contributed by CD73 on MSCs that cooperated with CD39 and CD73 on activated T cells to produce adenosine, resulting in inhibition of T-cell proliferation. Furthermore, MSCs increased the expression of CD73 on CD4(+) T cells, and transforming growth factor-beta1 (TGF-beta1) was the only tested cytokine that contributed to upregulation of CD73. Hence, our study demonstrates that the CD73/adenosine pathway involves the immunomodulatory function of MSCs in autoimmune responses.

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inical significance of CD79b expression in CLL patients and its possible value for the evaluation of minimal residual disease (MRD) was explored. A total of 15 peripheral blood (PB) samples from healthy blood donors, five bone marrow (BM) samples from normal donors and 40 PB samples from CLL untreated patients were included in the study. In addition we studied the expression of CD79b in B lymphocytes from five CLL patients after fludarabine treatment in order to support our method. The expression of CD79b in B lymphocytes from PB was analyzed by flow cytometry, using simultaneous staining with the Mabs CD22, CD79b, CD19 and CD5, CD79b and CD19. Since normal immature bone marrow B cells are CD79b-/dim+ on their surface, in BM samples we used the combination CD45, CD79b and CD19 selecting mature B lymphocytes according to their bright CD45 intensity. Cell acquisition was performed in two consecutive steps using a live gate drawn on SSC/CD19+ cells. For data analysis, the PAINT-A-GATE PRO software (Becton Dickinson) was used. Dilution experiments of CD79b- CLL cells and CD79bdim+ CLL cells with normal PB and BM cells were performed in order to assess the sensitivity level of the technique for detection of CD79b-/dim+residual CLL cells. All B lymphocytes from normal samples showed reactivity for the CD79b antigen. In contrast, CD79b was absent in 18/40 CLL patients (42.5%) and 20/40 CLL cases (50%) exhibited a low CD79b expression. Therefore, CD79b- B lymphocytes would be restricted to the CLL population and thus could be considered a 'tumor phenotype' for monitoring MRD in CLL patients. Dilution experiments indicate that the detection limit with this marker almost reaches the levels obtained by molecular biology methods as the PCR technique. All cases studied after fludarabine presented leukemic cells in their PB or BM samples detected by flow cytometry. Upon comparing the clinical and morphological characteristics of CD79b- and CD79b+ cases, all atypical CLL cases included in the present study were CD79b+ and advanced clinical stage (B and C Binet stage) was most frequently observed in CD79b+ cases than in CD79b- cases.

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aptor CD79. However, mutations in BTK or in downstream components such as CARMA1/CARD11 can render lymphomas Ibrutinib resistant. Therefore, we assessed here the simultaneous inhibition of BTK and the protease MALT1 that acts downstream of CARMA1 and is essential for ABC DLBCL tumor growth. We show that in CD79 mutant cells BTK is a crucial upstream regulator of MALT1, but dispensable in CARMA1 mutant ABC DLBCL. Combined inhibition of BTK by Ibrutinib and MALT1 by S-Mepazine additively impaired MALT1 cleavage activity and expression of NF-kappaB pro-survival factors. Thereby, combinatorial Ibrutinib and S-Mepazine treatment enhanced killing of CD79 mutant ABC DLBCL cells. Moreover, while expression of oncogenic CARMA1 in CD79 mutant cells conferred Ibrutinib resistance, double mutant cells were still sensitive to MALT1 inhibition by S-Mepazine. Thus, based on the genetic background combinatorial BTK and MALT1 inhibition may improve effectiveness of therapeutic treatment and reduce the chances for the development of drug resistances.

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for the disulfide bond between Igalpha and Igbeta. This patient has a small percentage of surface IgM(dim) B cells in the peripheral circulation (0.08% compared with 5-20% in healthy controls). Using expression vectors in 293T cells or Jurkat T cells, we show that the mutant Igbeta can form disulfide-linked complexes and bring the mu H chain to the cell surface as part of the BCR but is inefficient at both tasks. The results show that minor changes in the ability of the Igalpha/Igbeta complex to bring the BCR to the cell surface have profound effects on B cell development.

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creased levels of the nucleotide ATP and the nucleoside adenosine in bronchoalveolar lavage fluid (BALF) of wild-type (WT) C57BL/6 mice. Influenza-induced acute lung injury (ALI) was highly attenuated in A1-adenosine receptor-knockout mice. Because AMP hydrolysis by the ecto-5'-nucleotidase (CD73) plays a central role in and is rate-limiting for generation of adenosine in the normal lung, we hypothesized that ALI would be attenuated in C57BL/6-congenic CD73-knockout (CD73-KO) mice. Infection-induced hypoxemia, bradycardia, viral replication, and bronchoconstriction were moderately increased in CD73-KO mice relative to WT controls. However, postinfection weight loss, pulmonary edema, and parenchymal dysfunction were not altered. Treatment of WT mice with the CD73 inhibitor 5'-(alpha,beta-methylene) diphosphate (APCP) also had no effect on infection-induced pulmonary edema but modestly attenuated hypoxemia. BALF from CD73-KO and APCP-treated WT mice contained more IL-6 and CXCL-10/IFN-gamma-induced protein 10, less CXCL-1/keratinocyte chemoattractant, and fewer neutrophils than BALF from untreated WT controls. BALF from APCP-treated WT mice also contained fewer alveolar macrophages and more transforming growth factor-beta than BALF from untreated WT mice. These results indicate that CD73 is not necessary for development of ALI following influenza A virus infection and suggest that tissue-nonspecific alkaline phosphatase may be responsible for increased adenosine generation in the infected lung. However, they do suggest that CD73 has a previously unrecognized immunomodulatory role in influenza.

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chain allele and five samples that had normal immunoglobulin heavy-chain allelic exclusion. All leukemia cell samples stained poorly with monoclonal antibodies specific for extracellular epitopes of CD79b. However, all samples expressed functional CD79b genes, regardless of whether they did or did not express more than one immunoglobulin heavy-chain allele. We identified variant CD79b genes that had conservative base substitutions restricted to regions encoding the extracellular immunoglobulin-like domain of CD79b. However, these variants were not restricted to samples lacking immunoglobulin heavy-chain allelic exclusion and most likely reflect genetic polymorphism. Collectively, these data indicate that the unusual expression of more than one immunoglobulin heavy allele by CLL B cells is not associated with structural, nonconservative mutations in the signal-transduction domains of CD79b. (Blood. 2000;95:2725-2727)

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ont-weight:700;'>CD73 in fibrosis development after thoracic irradiation. Exposure of wild-type C57BL/6 mice to a single dose (15 Gray) of whole thorax irradiation triggered a progressive increase in CD73 activity in the lung between 3 and 30 weeks postirradiation. In parallel, adenosine levels in bronchoalveolar lavage fluid (BALF) were increased by approximately 3-fold. Histologic evidence of lung fibrosis was observed by 25 weeks after irradiation. Conversely, CD73-deficient mice failed to accumulate adenosine in BALF and exhibited significantly less radiation-induced lung fibrosis (P < 0.010). Furthermore, treatment of wild-type mice with pegylated adenosine deaminase or CD73 antibodies also significantly reduced radiation-induced lung fibrosis. Taken together, our findings demonstrate that CD73 potentiates radiation-induced lung fibrosis, suggesting that existing pharmacologic strategies for modulating adenosine may be effective in limiting lung toxicities associated with the treatment of thoracic malignancies. Cancer Res; 76(10); 3045-56. (c)2016 AACR.

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hingolipid of the globo series. Recently, it was shown that c.631C > G mutation in A4GALT, which causes p.Q211E substitution in the open reading frame of the enzyme, broadens the enzyme specificity, making it able also to synthesize Gal(alpha1-4)GalNAc moiety, which constitutes the defining terminal disaccharide of the NOR antigen (carried by two glycosphingolipids: NOR1 and NOR2). Terminal Gal(alpha1-4)Gal disaccharide is also present in another glycosphingolipid blood group antigen, called P1, which together with P(k) and NOR comprises the P1PK blood group system. Despite several attempts, it was never clearly shown that P1 antigen is synthesized by Gb3/CD77 synthase, leaving open an alternative hypothesis that there are two homologous alpha1,4-galactosyltransferases in humans. In this study, using recombinant Gb3/CD77 synthase produced in insect cells, we show that the consensus enzyme synthesizes both the P(k) and P1 antigens, while its p.Q211E variant additionally synthesizes the NOR antigen. This is the first direct biochemical evidence that Gb3/CD77 synthase is able to synthesize two different glycosphingolipid antigens: P(k) and P1, and when p.Q211E substitution is present, the NOR antigen is also synthesized.

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een elucidated. METHODS: Soluble CD72 was analyzed in the serum of 159 SLE patients, 40 rheumatoid arthritis (RA) patients, and 100 healthy individuals. Correlations between sCD72 and SLE disease activity (SLEDAI) were assessed. RESULTS: Soluble CD72 was found increased in SLE patients, when compared to both RA patients and healthy individuals (20.2 +/- 1.2 ng/ml; 10.6 +/- 4.6 ng/ml and 7.2 +/- 3.3 ng/ml; p < 0.001). Soluble CD72 level was significantly higher in SLE patients with renal involvement than in patients without (31.8 +/- 2.3 ng/ml vs 13.9 +/- 0.9 ng/ml; p < 0.001) and also with the presence of auto-antibodies. CONCLUSION: Soluble CD72 is significantly increased in SLE patients mainly in those with renal involvement. Increased sCD72 may become a potential biomarker for renal involvement in SLE.

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brake) offers a complimentary pathway to inducing anti-tumor immune responses. Here, we describe the mechanistic activity of a new clinical therapeutic, MEDI9447, a human monoclonal antibody that non-competitively inhibits CD73 activity. Epitope mapping, structural, and mechanistic studies revealed that MEDI9447 antagonizes CD73 through dual mechanisms of inter-CD73 dimer crosslinking and/or steric blocking that prevent CD73 from adopting a catalytically active conformation. To our knowledge, this is the first report of an antibody that inhibits an enzyme's function through 2 distinct modes of action. These results provide a finely mapped epitope that can be targeted for selective, potent, and non-competitive inhibition of CD73, as well as establish a strategy for inhibiting enzymes that function in both membrane-bound and soluble states.

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t:700;'>CD79a/CD79b heterodimer. We previously showed that the intracellular synthesis of BCR components, from transcription onward, is normal. Here, we investigated the glycosylation status and cellular localization of mu, CD79a, and CD79b chains in 10 CLL patients differing in surface immunoglobulin M (IgM) expression. We reported a severe impairment of the glycosylation and folding of mu and CD79a. These defects were associated with the retention of both chains in the endoplasmic reticulum and lower levels of surface IgM expression. In contrast, no clear impairment of glycosylation and folding was observed for CD79b. No sequence defects were identified for BCR components and for the chaperone proteins involved in BCR folding processes. These data show, for the first time, that lower levels of BCR surface expression observed in CLL are accounted for by an impaired glycosylation and folding of the mu and CD79a chains.

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r institution and investigated the frequency of MYD88 L265P and CD79B (exon 5) mutation in 29 eligible cases using Sanger sequencing. Clinically, PA-DLBCL was predominant in elderly male patients with advanced clinical stage and poor outcomes. Morphologically, the tumors often showed a sinusoidal and/or cohesive pattern with condensed chromatin and inconspicuous nucleolus which mimicked neuroendocrine carcinoma. Moreover, increased Reed-Sternberg-like cells were observed frequently. These confounding morphologic manifestations may lead to misdiagnosis. Genetically, PA-DLBCL harbored a high prevalence of MYD88 L265P (24%) and CD79B mutations (52%) which may be involved in lymphomagenesis. The CD79B mutation was significantly associated with a worse prognosis. A novel Histo-Molecular Classification system (4 categories) was proposed based on correlation with genetic changes. Generally, the neuroendocrine carcinoma-like type was associated with CD79B mutation, whereas the RS-like cell type indicated MYD88 L265P. The biphasic type was correlated with coexisting mutations of MYD88 and CD79B, whereas the common type implied no mutation. Furthermore, the common type showed significantly better survival. In conclusion, the proposed new category system could indicate the genetic changes as well as facilitate risk stratification to guide treatment and predict prognosis. Although this study augmented our understanding of PA-DLBCL, further analysis is required to validate our results and extend them to extranodal DLBCL at other sites.

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rtant role in development of priapism. A key enzyme in the adenosine pathway is CD73, an ecto-5'-nucleotidase (5'-ribonucleotide phosphohydrolase; EC 3.1.3.5) which catalyzes the conversion of adenosine mononucleotides to adenosine. In the present study we investigated how sickle cell disease and hypoxia regulate the interplay between opiorphin and CD73. In the corpora of sickle cell mice we observed significantly elevated expression of both the mouse opiorphin homolog mSmr3a (14-fold) and CD73 (2.2-fold) relative to non-sickle cell controls at a life stage before the exhibition of priapism. Sickle cell disease has a pronounced hypoxic component, therefore we determined if CD73 was also modulated in in vitro corporal smooth muscle (CSM) models of hypoxia. Hypoxia significantly increased CD73 protein and mRNA expression by 1.5-fold and 2-fold, respectively. We previously demonstrated that expression of another component of the adenosine signaling pathway, the adensosine 2B receptor, can be regulated by sialorphin (the rat opiorphin homolologue), and we demonstrate that sialorphin also regulates CD73 expression in a dose- and time-dependent fashion. Using siRNA to knockdown sialorphin mRNA expression in CSM cells in vitro, we demonstrate that the hypoxic upregulation of CD73 is dependent on the upregulation of sialorphin. Overall, our data provide further evidence to support a role for opiorphin in CSM in regulating the cellular response to hypoxia or sickle cell disease by activating smooth muscle relaxant pathways.

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eta gene was 3.1 kb in length with six exons and was separated by 3.3 and 9.3 kb from Na-channel and GH genes, respectively. Rat B29/Ig-beta protein comprised 228 amino acids, and its amino acid sequence was 85 and 69% identical with the mouse and human counterparts, respectively. With the long-area PCR method, genomic DNA connecting human SkM Na-channel (SCN4A) and B29/Ig-beta (CD79B) genes and CD79B and GH (GH1) genes was amplified, and the physical linkage of SCN4A/CD79B/ GH1 genes in the human genome was established. The human CD79B gene was separated by 6.3 and 10.5 kb from the SCN4A and GH1 genes, respectively.

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ins restrictive and controversial. This study aims to investigate whether microglia transform into novel subtypes in VaD. Chronic cerebral hypoperfusion (CCH) rat model was constructed to mimic VaD. Microglia were isolated via magnetic-activated cell sorting and analyzed by single-cell RNA sequencing (scRNA-seq) and bioinformatics. The findings inferred from scRNA-seq and bioinformatics were further validated through in vivo experiments. In this study, microglia were divided into eight clusters. The proportion of MG5 cluster was significantly increased in the white matter of the CCH group compared with the Sham group and was named chronic ischemia-associated microglia (CIAM). Immunity- and inflammation-related genes, including RT1-Db1, RT1-Da, RT1-Ba, Cd74, Spp1, C3, and Cd68, were markedly upregulated in CIAM. Enrichment analysis illustrated that CIAM possessed the function of evoking neuroinflammation. Further studies unveiled that Cd74 is associated with the most abundant GO terms involved in inflammation as well as cell proliferation and differentiation. In addition, microglia-specific Cd74 knockdown mediated by adeno-associated virus decreased the abundance of CIAM in the white matter, thereby mitigating inflammatory cytokine levels, alleviating white matter lesions, and improving cognitive impairment for CCH rats. These findings indicate that Cd74 is the core molecule of CIAM to trigger neuroinflammation and induce microglial differentiation to CIAM, suggesting that Cd74 may be a potential therapeutic target for VaD.

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e of proliferation, by flow cytometry in 265 patients with CLL. Combining bcl-2 with CD71 values, we defined three subgroups: (1) bcl2 - CD71-; (2) bcl2 + CD71+; and (3) bcl2 + CD71- or bcl2- CD71+. Both a shorter progression-free survival (PFS) and overall survival (OS) were observed in ZAP-70+ (p < 0.00001) and in patients with bcl2 + CD71+ (p < 0.00001 and p = 0.02). The patients with discordant in bcl2 + CD71- and bcl2- CD71+ showed an intermediate outcome. Noteworthy, patients with bcl2 + CD71+ showed a shorter PFS within ZAP-70 negative subgroup (p = 0.00009). In multivariate analysis of PFS, age (p = 0.005), beta-(2) microglobulin (B(2)-M) (p = 0.003), bcl-2 (p = 0.004), CD49d (p = 0.001), and ZAP-70 (p < 0.001) resulted to be significant prognostic factors. The independent prognostic significance of B(2)-M (p = 0.009) and bcl-2 (p = 0.03) was confirmed within ZAP-70 negative patients. Bcl-2 and CD71 can be considered as interesting progression indicators, which should be validated in an independent cohort of patients, to take timely therapeutic decisions in CLL.

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zation on normal tissue cells, complement regulation has to be selectively targeted to the malignant cells. In this study, anti-mCRP small interfering RNAs (siRNAs) were encapsulated in transferrin-coupled lipoplexes for the specific delivery to transferrin receptor CD71(high) expressing BT474, DU145, and SW480 as well as corresponding CD71-knockdown (CD71(low)) tumor cells. Targeted delivery with transferrin-siRNA-lipoplexes became possible by charge neutralization and resulted in efficient silencing of all three mCRPs up to 90%, which is dependent on their CD71 expression. The mCRP knockdown led to a significant increase of CDC on CD71(high) tumor cells by 68% in BT474, 58% in DU145, and 40% in SW480 cells but only slightly increased on CD71(low) cells. Downregulation of CD46 and CD55 significantly increased C3 opsonization only on CD71(high) tumor cells. Our results demonstrate for the first time that by specific delivery of anti-mCRP siRNA through transferrin receptor, complement regulation can be selectively neutralized, allowing specific antibody-mediated killing of tumor cells without affecting healthy bystander cells, which appears to be a suited strategy to improve antibody-based cancer immunotherapy.

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we detected the surface expression of CD79b in almost all non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia patients, suggesting that anti-CD79b-vcMMAE could be widely used in these malignancies. By using NHL cell lines to simulate a patient population we discovered that a minimal cell-surface expression level of CD79b was required for in vitro activity. Within the subpopulation of cell lines above this minimal threshold, we found that sensitivity to free MMAE, mutation of cancer genes, and cell doubling time were poorly correlated with in vitro activity; however, the expression level of BCL-XL was correlated with reduced sensitivity to anti-CD79b-vcMMAE. This observation was supported by in vivo data showing that a Bcl-2 family inhibitor, ABT-263, strikingly enhanced the activity of anti-CD79b-vcMMAE. Furthermore, anti-CD79b-vcMMAE was significantly more effective than a standard-of-care regimen, R-CHOP (ie, rituximab with a single intravenous injection of 30 mg/kg cyclophosphamide, 2.475 mg/kg doxorubicin, 0.375 mg/kg vincristine, and oral dosing of 0.15 mg/kg prednisone once a day for 5 days), in 3 xenograft models of NHL. Together, these data suggest that anti-CD79b-vcMMAE could be broadly efficacious for the treatment of NHL.

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into the bladder lumen while upregulating MIF and CD74 (MIF receptor) in the bladder. Because the effects of persistent cystitis on MIF and CD74 are not known, MIF and CD74 changes in the bladder were examined after short-term (1-day) or persistent (8-day) cyclophosphamide (CYP)-induced bladder inflammation. Anesthetized male Sprague-Dawley rats received either a single CYP treatment (150 mg/kg, ip; saline, control) and examined 1 day after treatment (short-term), or repeated CYP doses (20-75 mg/ kg, ip; saline, control; every third day for 8 days) and examined after 8 days of treatment (persistent). MIF protein levels in urine and bladder were determined. In addition, Mif, CD74, and cox-2 expression in the bladder was determined. Histology verified cystitis and MIF and CD74 immunoreactivity in the bladder. Repeated CYP doses were decreased to avoid toxicity. Short-term or repeated low CYP doses (40 mg/kg; 8 days) increased urinary MIF and decreased bladder MIF amounts while upregulating bladder Mif and CD74 mRNA expression. Persistent CYP-induced bladder inflammation (even at 40 mg/kg; 8-day treatment) also upregulated other inflammatory cytokines (CCL5, IL-11, iNOS) in the bladder. Short-term and persistent (low dose) CYP cystitis are associated with markedly increased MIF release into the urine and upregulation of Mif and CD74 in bladder. This supports the hypothesis that MIF and CD74 play a significant role in both acute and persistent stages of bladder inflammation.